We were getting the file by luck, from one of the paths in -I, fix it to
get it from the proper place:

  $ cd tools/include/uapi/asm/
  [acme@quaco asm]$ grep include bitsperlong.h
  #include "../../arch/x86/include/uapi/asm/bitsperlong.h"
  #include "../../arch/arm64/include/uapi/asm/bitsperlong.h"
  #include "../../arch/powerpc/include/uapi/asm/bitsperlong.h"
  #include "../../arch/s390/include/uapi/asm/bitsperlong.h"
  #include "../../arch/sparc/include/uapi/asm/bitsperlong.h"
  #include "../../arch/mips/include/uapi/asm/bitsperlong.h"
  #include "../../arch/ia64/include/uapi/asm/bitsperlong.h"
  #include "../../arch/riscv/include/uapi/asm/bitsperlong.h"
  #include "../../arch/alpha/include/uapi/asm/bitsperlong.h"
  #include <asm-generic/bitsperlong.h>
  $ ls -la ../../arch/x86/include/uapi/asm/bitsperlong.h
  ls: cannot access '../../arch/x86/include/uapi/asm/bitsperlong.h': No such file or directory
  $ ls -la ../../../arch/*/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 237 ../../../arch/alpha/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 841 ../../../arch/arm64/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 966 ../../../arch/hexagon/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 234 ../../../arch/ia64/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 100 ../../../arch/microblaze/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 244 ../../../arch/mips/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 352 ../../../arch/parisc/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 312 ../../../arch/powerpc/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 353 ../../../arch/riscv/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 292 ../../../arch/s390/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 323 ../../../arch/sparc/include/uapi/asm/bitsperlong.h
  -rw-rw-r--. 1 320 ../../../arch/x86/include/uapi/asm/bitsperlong.h
  $

Found while fixing some other problem, before it was escaping the
tools/ chroot and using stuff in the kernel sources:

    CC       /tmp/build/perf/util/find_bit.o
In file included from /git/linux/tools/include/../../arch/x86/include/uapi/asm/bitsperlong.h:11,
                 from /git/linux/tools/include/uapi/asm/bitsperlong.h:3,
                 from /git/linux/tools/include/linux/bits.h:6,
                 from /git/linux/tools/include/linux/bitops.h:13,
                 from ../lib/find_bit.c:17:

  # cd /git/linux/tools/include/../../arch/x86/include/uapi/asm/
  # pwd
  /git/linux/arch/x86/include/uapi/asm
  #

Now it is getting the one we want it to, i.e. the one inside tools/:

    CC       /tmp/build/perf/util/find_bit.o
  In file included from /git/linux/tools/arch/x86/include/uapi/asm/bitsperlong.h:11,
                   from /git/linux/tools/include/linux/bits.h:6,
                   from /git/linux/tools/include/linux/bitops.h:13,

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-8f8cfqywmf6jk8a3ucr0ixhu@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>